I'm missing an explanation of what would happen if Black, after White's correct move, plays Bxc3 followed by Na4, since this plan was supposed to be a threat after other White moves...
Ok, an explanation has been added in the lesson.
I'm missing an explanation of what would happen if Black, after White's correct move, plays Bxc3 followed by Na4, since this plan was supposed to be a threat after other White moves...